Gentex Corporation designs, develops, manufactures, markets, and supplies digital vision, connected car, premium audio, dimmable glass, fire protection technologies, medical devices, and others. Its segments include Automotive Products, Premium Audio Products and Other. The Automotive Products segment designs, develops, manufactures and markets interior and exterior automatic-dimming automotive rearview mirrors that utilize proprietary electrochromic technology to dim in proportion to the amount of headlight glare from trailing vehicle headlamps. Its Premium Audio Products segment designs, manufactures, markets, and distributes high quality audio equipment created to deliver superior sound quality and performance, including premium loudspeakers, architectural speakers and others. The other segment includes fire protection, dimmable aircraft windows, nanofiber, medical, and biometrics. It manufactures photoelectric smoke detectors and alarms, visual signalling alarms, and others.